Fractal spectrum of charge carriers in quasiperiodic graphene structures

J Phys Condens Matter. 2010 Nov 24;22(46):465305. doi: 10.1088/0953-8984/22/46/465305. Epub 2010 Nov 5.

Abstract

In this work we investigate the interaction of charge carriers in graphene with a series of p-n-p junctions arranged according to a deterministic quasiperiodic substitutional Fibonacci sequence. The junctions create a potential landscape with quantum wells and barriers of different widths, allowing the existence of quasi-confined states. Spectra of quasi-confined states are calculated for several generations of the Fibonacci sequence as a function of the wavevector component parallel to the barrier interfaces. The results show that, as the Fibonacci generation is increased, the dispersion branches form energy bands distributed as a Cantor-like set. Besides, for a quasiperiodic set of potential barriers, we obtain the electronic tunneling probability as a function of energy, which shows a striking self-similar behavior for different generation numbers.

Publication types

  • Research Support, Non-U.S. Gov't